The project described in this report has involved two general areas: 1)\the identification of and regulatory mechanisms involved in the biosynthetic and degradative pathways of Gamma-hydroxybutyrate (GHB), a naturally occuring compound in mammalian brain which is thought to function either as a neuromodulator or as a neurotransmitter, and 2) the study of certain pharmalogical effects of GHB especially those effects which bear a close resemblance to those of opiates such as morphine. The focus of this project will now be on the role of GHB at the cellular level in the central nervous system with an emphasis on the biochemical events which mediate its action.